Rivals are already selling and bigger screen phones, also known as "phablets," a contraction of phone and tablet. The most well known are Samsung's Galaxy Note handsets, the latest of which has a 5.5-inch screen. In January, Chinese vendor Huawei unveiled a device with a 6.1-inch screen, the Ascend Mate.

Demand for phones with 5-inch or larger screens will more than double this year, with shipments projected to reach 60 million units, according to research firm IHS iSuppli.

Financially, HTC has been struggling with profitability, due to the intense competition from the likes of Apple and Samsung. For this year's first quarter, HTC projects its revenue will range between NT$50 billion (US$1.7 billion) and NT$60 billion, which could result in a slight dip in sales from the previous quarter.

The company, however, is hoping to change its fortunes with the launch of its next handsets, with rumors online pointing to the unveiling of a new flagship smartphone in February.

"We certainly hope the announcement and the launch of the 'hero' products will carry the new product line," Chang said.

The Taiwanese vendor is also expanding in mainland China, now the world's largest market for smartphones. Although HTC wants to be known as a premium brand, the company plans to release more handsets at the lower end in the Chinese market, priced between 1000 yuan ($318) and 2000 when bought without a contract.

"We are going to go down, but we won't go below 1000 yuan," he said. "We still believe there is room to play from 1000 to 2000."